Why is my roof covered in green?
Quick answer: It’s a build-up of algae, moss and lichen. Dust, pollen and leaf debris lodge in the fabric; bird droppings act like fertiliser; and once the waterproofing wears, the hood stays damp — perfect for green growth, especially on cars parked under trees or in shade. Deep-clean the roof, rinse thoroughly, then re-proof and keep it washed to prevent regrowth.
A cabriolet roof can quickly become the perfect growing media for fauna. Dust from the air contains all the macro and micro nutrients plants need to live. Your roof gets plenty of sunshine, so all that is required is rain, something we have no shortage of.
So if your hood gets dirty, you are creating a garden perfect for moss and algae. It's an indicator of a dirty hood, which is the cause and a far bigger problem, because the organics growing on your hood, while difficult to remove, do very little damage. Dirt, however, is abrasive, so every time you put your hood down and bring it back up, the grit trapped within the fibres begins to grind away causing wear marks which are permanent damage.
IMPORTANT! Do not attempt to blast this green out with a pressure washer. Algae is part bacteria, part fungus, and it has tendrils which weave into the fibres. It holds on tight! If you are using enough pressure to blast it out of your roof, then you are using enough pressure to damage the roof. The correct way to remove it is brushing with a detergent, which will break down organic material.
If you start to see roof green on your soft top, we recommend a proper cleaning.
Written by Danny Argent. Last updated 08/09/2025 15:56
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Service: Convertible Roof Cleaning
Our Specialist cabriolet hood restoration service was developed, over 30 years, into a process which restores and protects your soft-top. -
How to look after a convertible roof
Tips and tricks for maintaining your cabriolet hood and preventing your soft top from going green.